﻿using System;
using System.CodeDom.Compiler;
using System.IO;
using System.Reflection;
using System.Text;
using Microsoft.CSharp;


namespace Wrox.ProCSharp.Assemblies
{
    public class CodeDriver : MarshalByRefObject
    {
        private string prefix =
           "using System;" +
           "public static class Driver" +
           "{" +
           "   public static void Run()" +
           "   {";

        private string postfix =
           "   }" +
           "}";


        public string CompileAndRun(string input, out bool hasError)
        {
            hasError = false;
            string returnData = null;

            CompilerResults results = null;
            using (var provider = new CSharpCodeProvider())
            {
                var options = new CompilerParameters();
                options.GenerateInMemory = true;

                var sb = new StringBuilder();
                sb.Append(prefix);
                sb.Append(input);
                sb.Append(postfix);

                results = provider.CompileAssemblyFromSource(
                      options, sb.ToString());
            }

            if (results.Errors.HasErrors)
            {
                hasError = true;
                var errorMessage = new StringBuilder();
                foreach (CompilerError error in results.Errors)
                {
                    errorMessage.AppendFormat("{0} {1}", error.Line,
                          error.ErrorText);
                }
                returnData = errorMessage.ToString();
            }
            else
            {
                TextWriter temp = Console.Out;
                var writer = new StringWriter();
                Console.SetOut(writer);
                Type driverType = results.CompiledAssembly.GetType("Driver");

                driverType.InvokeMember("Run", BindingFlags.InvokeMethod |
                      BindingFlags.Static | BindingFlags.Public,
                      null, null, null);
                Console.SetOut(temp);

                returnData = writer.ToString();
            }

            return returnData;
        }
    }
}
